Lymphatic transport of Methylnortestosterone undecanoate (MU) and the bioavailability of methylnortestosterone are highly sensitive to the mass of coadministered lipid after oral administration of MU.

The contribution of lymphatic transport to the oral bioavailability of methylnortestosterone (M) after oral administration of the lipophilic prodrug methylnortestosterone undecanoate (MU) has been evaluated, and the sensitivity of lymphatic MU transport to lymphatic lipid transport has been investigated. M and MU were administered intravenously and orally to greyhound dogs to determine absolute bioavailability after oral dosing of MU. MU was also administered orally with differing quantities of food (lipid) to lymph duct-cannulated greyhound dogs to investigate the relative roles of lymph versus blood transport on M bioavailability and the effect of lipid load on systemic exposure.

Oral bioavailability assessment and intestinal lymphatic transport of Org 45697 and Org 46035, two highly lipophilic novel immunomodulator analogues.

Org 45697 (MW 600.7, clogP 7.92, soybean oil solubility 50 mg/g) and Org 46035 (MW 601.

Contribution of lymphatically transported testosterone undecanoate to the systemic exposure of testosterone after oral administration of two andriol formulations in conscious lymph duct-cannulated dogs.

Orally administered testosterone (T) is ineffective in the treatment of male androgen deficiency syndromes due to extensive presystemic first-pass metabolism. In contrast, the lipophilic long-chain ester testosterone undecanoate (TU) exhibits androgenic activity that has been attributed to formation of T via systemic hydrolysis of lymphatically transported TU. However, there are no definitive data regarding the oral bioavailability of TU or the extent to which lymphatically transported TU contributes to the systemic availability of T after oral TU administration.